Most nurses will care for and provide health information about cancer to a patient at some point in their careers. Cancer care will change dramatically in the coming years as a result of the translation of information gained from the Human Genome Project into clinical practice and the enhanced understanding of cancer at a molecular level. A select group of cancers, known as hereditary cancers, result from mutations in the germline that confer a greatly increased lifetime risk of developing cancer. Advances in technology and discoveries stemming from the Human Genome Project now provide the means to test individuals for the presence of mutations associated with some known hereditary cancer syndromes. Of particular importance to gastroenterology nurses are hereditary colorectal cancer syndromes. Although many ethical, legal, and psychosocial issues associated with testing remain unresolved, predisposition genetic testing is having a significant impact on health care. Nurses will have vital roles in the future assessing patients and their family members for increased cancer risk, educating them about the availability of testing, making referrals for cancer genetic counseling and risk assessment, and providing follow-up care in the community for patients found to be at increased risk.